Liner drilling using temporarily sealed liner

ABSTRACT

A drilling apparatus including a first cylindrical layer including a plurality of cylindrical members, and a second cylindrical layer including a plurality of elongate members, the plurality of cylindrical members and the plurality of elongate members arranged to form a plurality of spaces between an outer diameter of the first cylindrical layer and an inner diameter of the second cylindrical layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 61/570,508, entitled “Liner Drilling Using TemporarilySealed Liner,” filed Dec. 14, 2011, which is herein incorporated byreference.

FIELD OF DISCLOSURE

The present disclosure relates generally to the field of drilling andprocessing of wells. More particularly, one or more embodiments relateto oil and gas well drilling while simultaneously installing a liner inthe well bore.

BACKGROUND

Oil and gas wells are conventionally drilled with drill pipe to acertain depth, then casing is run and cemented in the well. The operatormay then drill the well to a greater depth with drill pipe and cementanother string of casing. In this type of system, each string of casingextends to the surface wellhead assembly.

In some well completions, an operator may install a liner rather thananother string of casing. The liner is made up of joints of pipe in thesame manner as casing. Also, the liner is normally cemented into thewell. However, the liner does not extend back to the wellhead assemblyat the surface. Instead, it is secured by a liner hanger to the laststring of casing just above the lower end of the casing. The operatormay later install a tieback string of casing that extends from thewellhead downward into engagement with the liner hanger assembly.

When installing a liner, in most cases, the operator drills the well tothe desired depth, retrieves the drill string, then assembles and lowersthe liner into the well. A liner top packer may also be incorporatedwith the liner hanger. A cement shoe with a check valve will normally besecured to the lower end of the liner as the liner is made up. When thedesired length of liner is reached, the operator attaches a liner hangerto the upper end of the liner, and attaches a running tool to the linerhanger. The operator then runs the liner into the wellbore on a stringof drill pipe attached to the running tool. The operator sets the linerhanger and pumps cement through the drill pipe, down the liner and backup an annulus surrounding the liner. The cement shoe prevents backflowof cement back into the liner. The running tool may dispense a wiperplug following the cement to wipe cement from the interior of the linerat the conclusion of the cement pumping. The operator then sets theliner top packer, if used, releases the running tool from the linerhanger, and retrieves the drill pipe.

SUMMARY

According to one aspect of the disclosure, there is provided a drillingapparatus including a first cylindrical layer including a plurality ofcylindrical members, and a second cylindrical layer including aplurality of elongate members, the plurality of cylindrical members andthe plurality of elongate members arranged to form a plurality of spacesbetween an outer diameter of the first cylindrical layer and an innerdiameter of the second cylindrical layer.

According to another aspect of the disclosure, there is provided adrilling system including a drilling liner having a first cylindricallayer formed from a plurality of cylindrical members coupled inparallel, a second cylindrical layer formed from a plurality of elongatemembers coupled in parallel, the plurality of cylindrical members andthe plurality of elongate members arranged to form a plurality of spacesbetween an outer diameter of the first cylindrical layer and an innerdiameter of the second cylindrical layer, and a removable materialimpregnated in the plurality of spaces formed between the firstcylindrical layer and the second cylindrical layer, and a drill bitcoupled to the drilling liner.

According to another aspect of the disclosure, there is provided amethod of manufacturing a drilling liner apparatus, the method includingforming a first cylindrical layer having a first plurality ofperforations formed therethrough, forming a second cylindrical layerhaving a second plurality of perforations formed therethrough, in whichthe second plurality of perforations are in fluid communication with thefirst plurality of perforations, and impregnating one or more of thefirst plurality of perforations and the second plurality of perforationswith a removable material.

According to yet another aspect of the disclosure, there is provided amethod of drilling including drilling a well bore to a pre-determineddepth with a drill bit coupled to a drilling liner, the drilling linerhaving a plurality of perforations formed therethrough and a removablematerial impregnated in one or more of the plurality of perforations,removing the removable material impregnated in the plurality ofperforations, and producing a production fluid, wherein the productionfluid passes through the drilling liner.

Other aspects and advantages of the invention will be apparent from thefollowing description and the appended claims. The variouscharacteristics described above, as well as other features, will bereadily apparent to those skilled in the art upon reading the followingdetailed description, and by referring to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a partial top view of a slotted liner in accordance withembodiments disclosed herein.

FIG. 2 is a perspective view of a plurality of elongate members inaccordance with embodiments disclosed herein.

FIG. 3A is a partial top view of a slotted liner in accordance withembodiments disclosed herein.

FIG. 3B is a cross-sectional view of section A-B of the slotted liner ofFIG. 3A.

FIG. 4A is a partial cross-sectional view of a first cylindrical layerof a slotted liner without a removable material impregnated in gapsformed therein in accordance with embodiments disclosed herein.

FIG. 4B is a partial cross-sectional view of a first cylindrical layerand a second cylindrical layer of a slotted liner with a removablematerial impregnated in gaps formed therein in accordance withembodiments disclosed herein.

DETAILED DESCRIPTION

It is now recognized that there exists a need for improved and differentsystems and methods for oil and gas well drilling. Accordingly, one ormore embodiments of the present disclosure are directed to drillingapparatuses, methods, and systems for oil and gas well drilling whilesimultaneously installing a slotted liner in the well bore.Specifically, aspects of the present disclosure are directed to drillingapparatuses, methods, and systems to allow an oil and gas well to bedrilled with a slotted liner such that the slotted liner does not needto be installed separately after the well bore is drilled.

The following is directed to various exemplary embodiments of thedisclosure. Although one or more of these embodiments may be preferred,the embodiments disclosed should not be interpreted, or otherwise used,as limiting the scope of the disclosure, including the claims. Inaddition, those having ordinary skill in the art will appreciate thatthe following description has broad application, and the discussion ofany embodiment is meant only to be exemplary of that embodiment, and notintended to suggest that the scope of the disclosure, including theclaims, is limited to that embodiment.

Certain terms are used throughout the following description and claimsthat refer to particular features or components. As those havingordinary skill in the art will appreciate, different persons may referto the same feature or component by different names. This document doesnot intend to distinguish between components or features that differ inname but not function. The figures are not necessarily to scale. Certainfeatures and components herein may be shown exaggerated in scale or insomewhat schematic form and some details of conventional elements maynot be shown in interest of clarity and conciseness.

In the following discussion and in the claims, the terms “including” and“comprising” are used in an open-ended fashion, and thus should beinterpreted to mean “including, but not limited to . . . ” Also, theterm “couple” or “couples” is intended to mean either an indirect ordirect connection. Thus, if a first component is coupled to a secondcomponent, that connection may be through a direct connection, orthrough an indirect connection via other components, devices, andconnections. Further, the terms “axial” and “axially” generally meanalong or parallel to a central or longitudinal axis, while the terms“radial” and “radially” generally mean perpendicular to a centrallongitudinal axis.

Additionally, directional terms, such as “above,” “below,” “upper,”“lower,” etc., are used for convenience in referring to the accompanyingdrawings. In general, “above,” “upper,” “upward,” and similar termsrefer to a direction toward the earth's surface from below the surfacealong a borehole, and “below,” “lower,” “downward,” and similar termsrefer to a direction away from the surface along the borehole, i.e.,into the borehole, but is meant for illustrative purposes only, and theterms are not meant to limit the disclosure.

One or more embodiments of the present disclosure are directed to adrilling apparatus having a cylindrical layer, the cylindrical layerhaving a plurality of perforations formed therethrough, which may bereferred to as a slotted liner. The plurality of perforations may be anyopenings, gaps, or spaces formed through the cylindrical layer such thata fluid may pass from an outer surface of the cylindrical layer throughthe cylindrical layer to an inner surface of the cylindrical layer, andvice versa. For example, the plurality of perforations may be holes orslots formed through the cylindrical layer or gaps or spaces formedbetween adjacent cylindrical layers.

Further, the drilling apparatus may include a removable materialimpregnated in one or more of the plurality of perforations; in someembodiments, the removable material may be impregnated in each of theplurality of perforations. In one or more embodiments, the removablematerial may be stable when exposed to, or in combination with, drillingfluid or pills that may be used. For example, the removable material maybe chemically stable during drilling, thermally stable at drillingconditions, resilient with respect to frictional forces and other forcesthat may be encountered while drilling. The frictional forces and otherforces that may be encountered while drilling may be caused by theformation, particles in drilling fluid, and rotational forces/bendingforces of the downhole tool. Furthermore, the removable material may beof high enough viscosity so as to not flow significantly under suchexpected downhole conditions.

Once drilling and emplacement of the liner is completed, it would thenbe necessary to remove the removable material. Thus, the removablematerial may also be dissolvable, depolymerizable, degradable orotherwise capable of being broken down and removed from the perforationsor gaps when desired. For example, in one or more embodiments, theremovable material may be a dissolvable polymer impregnated in theplurality of perforations. In one or more embodiments, the dissolvablepolymer may be one of a water-stable polymer and an oil-stable polymer.In other words, the dissolvable polymer may be a polymer that does notbreak down or dissolve when exposed to water or oil based drillingfluids. For example, the removable material may be a water-stable, oilsoluble polymer; after drilling with a water-based mud, an oil-based mudor solvent may be used to remove the removable material. In otherembodiments, the dissolvable polymer according to embodiments disclosedherein may be a dissolvable polymer that does not break down or dissolvewhen exposed to either a water-based drilling mud or an oil-baseddrilling mud, but may be removed by other means, such as contact orexposure to select organic solvents, inorganic solvents, or other meansof dissolving, depolymerizing, softening, or degrading of the polymer.As such, the removable material according to embodiments herein mayinclude polymers, gels, or other chemical or physical networks that arewater soluble, hydrocarbon soluble, thermally degradable, thermallyunstable, photo-degradable and/or U.V. degradable. For example, theremovable material may include a cross-linked cellulosic network, anacid soluble polyamide, and other materials as may be readily envisionedbased on the above description.

Furthermore, those having ordinary skill in the art will appreciate thatthe removable material of the present disclosure may be any materialthat is removable by way of exposure to a specific material orsubstance. For example, the removable material of the present disclosuremay be a material removable by exposure to a specific removal material.In one or more embodiments, the removable material may be able tosustain high temperature and high pressure downhole conditions withoutbreaking down or dissolving, while still being able to dissolve whenexposed to a specific removal material, such as a solvent.

In one or more embodiments, the cylindrical layer may be a firstcylindrical layer and the drilling apparatus may include a secondcylindrical layer, which may be disposed within the first cylindricallayer. For example, in one or more embodiments, an outer diameter of thesecond cylindrical layer may be substantially equal to or smaller thanan inner diameter of the first cylindrical layer. In other words, thesecond cylindrical layer may be configured to be disposed within thefirst cylindrical layer, or vice versa.

In one or more embodiments, the first cylindrical layer may be formedfrom a plurality of cylindrical members coupled in parallel having afirst plurality of perforations formed therethrough. The cylindricalmembers may be of any cross-sectional shape, such as triangular,semi-circular, etc., as described later, formed to have an overallcircular or helical structure having a height and a diameter. Forexample, the first cylindrical members may be rings formed fromtriangular wire, where multiple rings may be arranged to form acylindrical structure, the first cylindrical layer. Further, in one ormore embodiments, the first plurality of perforations may include gapsformed between each of the plurality of cylindrical members. In one ormore embodiments, the plurality of cylindrical members may be coupled byway of spot welding. For example, the plurality of cylindrical membersmay be spot welded together to form the first cylindrical layer suchthat each of the elongate members extends in a direction that isparallel to one another, while leaving gaps between some or each of theplurality of elongate members such that fluid may pass between some oreach of the plurality of elongate members. In one or more embodiments,gaps may not necessarily be formed between each and every elongatemember of the first cylindrical layer. However, in one or moreembodiments, gaps may be formed between each and every elongate memberof the first cylindrical layer.

As discussed above, in one or more embodiments, the drilling apparatusmay include a second cylindrical layer. In one or more embodiments, thesecond cylindrical layer may include a second plurality of perforationsformed therethrough. Further, in one or more embodiments, the secondcylindrical layer may be formed from a plurality of elongate memberscoupled in parallel having a second plurality of perforations formedtherethrough. In one or more embodiments, the plurality of elongatemembers may be substantially similar to the plurality of cylindricalmembers. For example, a cross-section of the plurality of cylindricalmembers may be substantially identical to a cross-section of theplurality of elongate members. Further, in one or more embodiments, theplurality of cylindrical members may be formed from substantially thesame material as the plurality of elongate members. However, thosehaving ordinary skill in the art will appreciate that the plurality ofcylindrical members is not limited to being substantially similar to theplurality of elongate members. For example, while the cross-section ofeach of the first and the plurality of elongate members may besubstantially identical, a length of each of the first and the pluralityof elongate members may not necessarily be equivalent. Further, in oneor more embodiments, the cross-section of each of the first and theplurality of elongate members may not necessarily be identical.

Further, in one or more embodiments, the second plurality ofperforations may be in fluid communication with the first plurality ofperforations. In other words, in an embodiment in which the drillingapparatus, e.g., the slotted liner, includes the first cylindrical layerand the second cylindrical layer disposed within the first cylindricallayer, a fluid, e.g., a production fluid or a drilling fluid, may passfrom an outer surface of the first cylindrical layer through thedrilling apparatus to an inner surface of the second cylindrical layer,and vice versa. The gaps formed between the cylindrical members and theelongate members may define a flow path from the first plurality ofperforations to the second plurality of perforations

In one or more embodiments, the removable material may be impregnated inthe gaps formed in both the first cylindrical layer and the secondcylindrical layer such that a fluid, e.g., a production fluid or adrilling fluid, may not pass from an outer surface of the firstcylindrical layer through the drilling apparatus to an inner surface ofthe second cylindrical layer, and vice versa. For example, in one ormore embodiments, the removable material may be impregnated in the gapsformed between each of the plurality of cylindrical members and theplurality of elongate members such that a fluid may not pass from anouter surface of the first cylindrical layer through the drillingapparatus to an inner surface of the second cylindrical layer, and viceversa.

As used herein, the term “perforations” may refer to openings formedthrough a drilling apparatus, e.g., a slotted liner. For example, aslotted liner formed from two cylindrical layers having perforationsformed therethrough refers to openings formed through both the firstcylindrical layer and the second cylindrical layer. Each of the firstcylindrical layer and the second cylindrical layer may include “gaps”formed therein, e.g. formed between a plurality of cylindrical membersand between a plurality of elongate members. As used herein, the “gaps”formed in each of the first cylindrical layer and the second cylindricallayer may form the “perforations” formed through the slotted liner.Further, in one or more embodiments, “spaces” may be formed between thefirst cylindrical layer and the second cylindrical layer. These “spaces”may be in fluid communication with the “gaps” formed in each of thefirst cylindrical layer and the second cylindrical layer may also formthe “perforations” formed through the slotted liner.

Referring to FIG. 1, a partial top view of a slotted liner 100 accordingto embodiments disclosed herein is shown. As shown, the slotted liner100 includes a first cylindrical layer 101 and a second cylindricallayer 102. As discussed above, the first cylindrical layer 101 may beformed from a plurality of cylindrical members 103 and the secondcylindrical layer 102 may be formed from a plurality of elongate members104. In some embodiments, the first cylindrical layer 101 may be formedof a continuous structure, such as a triangular wire, helically wrappedaround the elongate members 104 of the second cylindrical layer 102(thus, the cylindrical members 103 may be considered as a portion of thehelix for the purposes of the additional discussions herein).

The plurality of cylindrical members 103 and the plurality of elongatemembers 104 may be coupled, such as by spot welding. For example, theplurality of cylindrical members 103 may be spot welded together to formthe first cylindrical layer 101 such that each of the plurality ofcylindrical members 103 extends in a direction that is parallel to oneanother, while leaving gaps (not shown) between some or each of theplurality of cylindrical members 103 such that fluid, e.g., a productionfluid or a drilling fluid, may pass between some or each of theplurality of cylindrical members 103. Alternatively, in one or moreembodiments, the first cylindrical layer 101 may be formed by casting.As such, the first cylindrical layer 101 of the present disclosure isnot limited to being formed from coupling a plurality of cylindricalmembers 103, as the first cylindrical layer 101, which may include theplurality of cylindrical members 103, may be formed together, e.g., byway of a casting process.

Similarly, the plurality of elongate members 104 may be coupled togetherto form the second cylindrical layer 102 such that each of the pluralityof elongate members 104 extends in a direction that is parallel to oneanother, while leaving gaps 106 between some or each of the plurality ofelongate members 104 such that fluid, e.g., a production fluid or adrilling fluid, may pass between some or each of the plurality ofcylindrical members 104. As discussed above, gaps may not necessarily beformed between each and every elongate member of the first cylindricallayer 101 and/or the second cylindrical layer 102. However, in one ormore embodiments, gaps may be formed between each and every elongatemember of the first cylindrical layer 101 and the second cylindricallayer 102. Alternatively, in one or more embodiments, the secondcylindrical layer 102 may be formed by casting. As such, the secondcylindrical layer 102 of the present disclosure is not limited to beingformed from coupling a plurality of elongate members 104, as the firstcylindrical layer 102, which may include the plurality of cylindricalmembers 104, may be formed together, e.g., by way of a casting process.

Each of the plurality of cylindrical members 103 and the plurality ofelongate members 104 may have a triangular cross section. In otherwords, the cross-section of each of the plurality of cylindrical members103 and the plurality of elongate members 104 is substantiallytriangular in cross section. Having triangular elongate members form thefirst cylindrical layer 101 and/or the second cylindrical layer 102 mayresult in substantially wedge-shaped gaps or spaces, e.g., gaps 106,formed between one or more triangular elongate members. As will bediscussed further below, wedge-shaped spaces formed between theplurality of elongate members of the first cylindrical layer 101 and/orthe second cylindrical layer 102 may prevent a removable material (notshown) from inadvertently escaping from the gaps or spaces formedbetween one or more triangular elongate members. However, those havingordinary skill in the art will appreciate that the cross-section of eachof the plurality of cylindrical members and the plurality of elongatemembers, according to aspects described herein, is not limited to beingtriangular in shape. For example, the cross-section of each of theplurality of cylindrical members and the plurality of elongate membersmay be circular, semi-circular, rectangular, pentagonal, hexagonal,octagonal, or any other shape.

The second cylindrical layer 102 may be disposed within the firstcylindrical layer 101, and the second cylindrical layer 102 may becoupled to the first cylindrical layer 101. For example, the secondcylindrical layer 102 may be coupled to the first cylindrical layer 101by way of spot welding. At the interface of the first and secondcylindrical layers, shown by the dotted circles in FIG. 1, the secondcylindrical layer 102 may be coupled to the first cylindrical layer 101by spot welding each of the plurality of elongate members 102, whichform the second cylindrical layer 102, to one or more cylindricalmembers of the first cylindrical layer 101. However, those havingordinary skill in the art will appreciate that, in one or moreembodiments, the first cylindrical layer 101 may be configured to bedisposed in the second cylindrical layer 102, and the second cylindricallayer 102 may be coupled to the first cylindrical layer 101.

Referring to FIG. 2, a perspective view of a plurality of elongatemembers 204 according to embodiments disclosed herein is shown. Asdiscussed above, each of the plurality of elongate members 204 may be atriangular elongate member. In other words, the cross-section of each ofthe plurality of elongate members 204 may be substantially triangular,which may result in wedge-shaped gaps formed between the elongatemembers 204. Further, the plurality of elongate members 204 may bearranged to form a cylindrical layer (not shown) such that each of theelongate members 204 extends in a direction that is parallel to oneanother, e.g., in the direction of axis 250, while leaving gaps, e.g.,the gaps 106 from FIG. 1, between some or each of the plurality ofelongate members 204 such that fluid, e.g., a production fluid or adrilling fluid, may pass between some or each of the plurality ofelongate members 204. Furthermore, as discussed above, the plurality ofelongate members 204 may be coupled together by way of spot welding.

In one or more embodiments, the cylindrical layer may be formed from aplurality of elongate members. For example, elongate members, such aselongate members 204, may be bent or curved to form the firstcylindrical layer and/or the second cylindrical layer. For example, inone or more embodiments, a plurality of elongate members may be bent orcurved such that a length of the elongate members may substantially forma circumference of the first cylindrical layer, e.g., the firstcylindrical layer 101 shown in FIG. 1. Alternatively, in one or moreembodiments, elongate members may be truncated to be of even length, ifnecessary, and arranged to form the second cylindrical layer, e.g., thesecond cylindrical layer 102 shown in FIG. 1, such that the length ofthe elongate members substantially forms a height of the secondcylindrical layer. Further, in one or more embodiments, the firstcylindrical layer and/or the second cylindrical layer may be formed byway of a casting process and may not necessarily be limited toarranging, bending or curving the elongate members forming the firstand/or second cylindrical layers. In other words, in one or moreembodiments, each of the first cylindrical layer and the secondcylindrical layer may be manufactured or formed as cylindrical layers.

Those having ordinary skill in the art will appreciate that the firstand second cylindrical layers, the cylindrical members 203 and theelongate members 204, may be formed from any substantially rigidmaterial known in the art. For example, in one or more embodiments, thecylindrical and elongate members may be formed from steel or any othersubstantially rigid material capable of withstanding high pressure, hightemperature downhole conditions as well as the torque and other forcesthat may be encountered during the drilling process.

Referring to FIG. 3A, a partial top view of a slotted liner 300according to embodiments disclosed herein is shown. As shown, theslotted liner 300 includes a first cylindrical layer 301 and a secondcylindrical layer 302. In one or more embodiments, the first cylindricallayer 301 may be formed from a plurality of cylindrical members 303 andthe second cylindrical layer 302 may be formed from a plurality ofelongate members 304.

The plurality of cylindrical members 303 and the plurality of elongatemembers 304 may be coupled, such as by spot welding. For example, theplurality of cylindrical members 303 may be arranged to form the firstcylindrical layer 301 such that each of the plurality of cylindricalmembers 303 extends in a direction that is parallel to one another,while leaving gaps (not shown) between some or each of the plurality ofcylindrical members 303 such that fluid, e.g., a production fluid or adrilling fluid, may pass between some or each of the plurality ofcylindrical members 303. Similarly, the plurality of elongate members304 may be arranged to form the second cylindrical layer 302 such thateach of the plurality of elongate members 304 extends in a directionthat is parallel to one another, while leaving gaps 306 between some oreach of the plurality of elongate members 304 such that fluid, e.g., aproduction fluid or a drilling fluid, may pass between some or each ofthe plurality of cylindrical members 304. The members of the firstand/or second cylindrical layers may then be coupled together, such asby spot welding, to form a cylindrical structure.

For example, the second cylindrical layer 302 may be coupled to thefirst cylindrical layer 301 by way of spot welding. As shown by thedotted circle in FIG. 3A, the second cylindrical layer 302 may becoupled to the first cylindrical layer 301 by spot welding each of theplurality of elongate members 302, which form the second cylindricallayer 302, to the first cylindrical layer 301. In one or moreembodiments, the welding may be continuous welding and may beaccomplished by resistivity welding.

As will be discussed further below, each of the gaps (not shown) formedin the first cylindrical layer and the gaps 306 formed in the secondcylindrical layer may be impregnated with a removable material (notshown). The impregnated removable material may prevent fluid, e.g., aproduction fluid or a drilling fluid, from passing through the firstcylindrical layer 301 and the second cylindrical layer 302. For example,a fluid, e.g., a drilling fluid, may be prevented from flowing fromwithin the slotted liner 300, i.e., in an outward radial directionindicated by arrow 351, by the impregnated removable material. Further,a fluid, e.g., a production fluid, may be prevented from flowing intothe slotted liner 300 from outside the slotted liner 300, i.e., in aninward radial direction indicated by arrow 352, by the impregnatedremovable material. Further, as will be discussed further below, thewedge-shaped geometry and orientation of each of the gaps may helpretain the impregnated removable material within each of the gaps whenthe impregnated removable material is under fluid pressure in both theinward radial direction and the outward radial direction.

Referring to FIG. 3B, a cross-sectional view of section A-B of theslotted liner 300 of FIG. 3A is shown. As discussed above, in one ormore embodiments, the plurality of cylindrical members 303 and/or theplurality of elongate members 304 may be bent or curved to form thefirst cylindrical layer 301 and the second cylindrical layer 302,respectively.

For example, as shown, a plurality of cylindrical members 303 forms acircumference of the first cylindrical layer 301. Further, as shown, theplurality of elongate members 304 may be arranged to form the secondcylindrical layer 302 such that the length of each of the plurality ofelongate members 304 substantially forms a height of the secondcylindrical layer 302. In other words, as shown, the plurality ofcylindrical members 303 extend in a first direction, and the pluralityof elongate members 304 extend in a second direction, in which the firstdirection is substantially perpendicular to the second direction,although other angles of orientation between the first and seconddirections may be used.

As shown, each of the plurality of cylindrical members 303 and theplurality of elongate members 304 has a triangular cross section. Inother words, the cross-section of each of the plurality of cylindricalmembers 303 and the plurality of elongate members 304 is substantiallytriangular. As discussed above, having triangular elongate members formthe first cylindrical layer 301 and/or the second cylindrical layer 302may result in substantially wedge-shaped gaps or spaces, e.g., gaps 305and 306, formed between the first plurality of triangular elongatemembers 303 and the second plurality of triangular elongate members 304,respectively. In one or more embodiments, the wedge-shaped gaps formedbetween the cylindrical members and elongate members may prevent aremovable material (not shown) from inadvertently escaping from the gapsor spaces 305, 306 formed between the cylindrical members 303 and theelongate members 304, respectively.

For example, as shown, the gaps 305 formed between each of the pluralityof cylindrical members 303 are substantially wedge-shaped, in which anapex of each of the wedge-shaped gaps 305 is oriented near an outerdiameter of the first cylindrical layer 301. In one or more embodiments,the apex of each of the wedge-shaped gaps 305 of the first cylindricallayer 301 may be considered the point of the wedge-shaped gap 305, e.g.,the corner of the triangle, which is most proximate to the outerdiameter of the first cylindrical layer 301. Similarly, the gaps 306formed between each of the plurality of elongate members 304 aresubstantially wedge-shaped, in which an apex of each of the wedge-shapedgaps 306 is oriented near an inner diameter of the second cylindricallayer 302. In one or more embodiments, the apex of each of thewedge-shaped gaps 306 of the second cylindrical layer 302 may beconsidered to be the point of the wedge-shaped gap 306, e.g., the cornerof the triangle, which is most proximate to the inner diameter of thesecond cylindrical layer 302.

The wedge-shaped nature and orientation of the gaps 305 formed in thefirst cylindrical layer 301 may prevent a removable material (not shown)that may be impregnated in each of the gaps 305 formed in the firstcylindrical layer 301 from escaping through the gaps 305 toward theouter diameter of the first cylindrical layer 301 such as due topressure and/or friction as a result of drilling fluid circulation,formation fluids, or contact with the formation itself. In one or moreembodiments, the normal force provided by the wedge structure may helpcontain the removable material within the gaps 305. For example, if theremovable material is impregnated in each of the gaps 305 formed in thefirst cylindrical layer 301, a fluid, e.g., a drilling fluid, may not beable to escape from within the slotted liner 300 because the removablematerial may block fluid flow therethrough. In other words, thewedge-shaped nature and orientation of the gaps 305 of the firstcylindrical layer 301 may help contain a fluid within the slotted liner300 with the impregnated removable material, which may allow the slottedliner to function as a non-perforated liner or casing, i.e., by allowingmud to flow through the slotted liner 300 without fluid escaping throughthe gaps 305.

Similarly, the wedge-shaped nature and orientation of the gaps 306formed in the second cylindrical layer 302 may prevent the removablematerial (not shown), which may also be impregnated in each of the gaps306 formed in the second cylindrical layer 302, from escaping throughthe gaps 306 toward the inner diameter of the second cylindrical layer.In one or more embodiments, the normal force provided by the wedgestructure may help contain the removable material within the gaps 306.For example, if the removable material is impregnated in each of thegaps 306 formed in the second cylindrical layer 302, a fluid, e.g., aproduction fluid, may not be able to enter the slotted liner 300 fromoutside of the slotted liner 300 because the removable material mayblock fluid flow therethrough. In other words, the wedge-shaped natureand orientation of the gaps 306 of the first cylindrical layer 302 mayhelp prevent a fluid from entering the slotted liner 300 with theimpregnated removable material, which may allow the slotted liner tofunction as a non-perforated liner or casing, i.e., by preventing fluidsfrom entering the slotted liner 300 through the gaps 306 and flowing upthrough the slotted liner 300 to the surface.

However, those having ordinary skill in the art will appreciate that thegaps 305, 306 formed in the first cylindrical layer 301 and the secondcylindrical layer 302, respectively, are not limited to beingwedge-shaped. In one or more embodiments, the gaps 305, 306 may betapered and may include a narrowing flow region which may be configuredto help retain a removable material within the gaps 305, 306. Forexample, in one or more embodiments, the plurality of cylindricalmembers 303 of the first cylindrical layer 301 and/or the plurality ofelongate members of the second cylindrical layer 302 may have a circularor semi-circular cross-section. These circular or semi-circularcross-sections may be arranged to form a tapered, narrowing flow regionbetween adjacent elongate members in each of the cylindrical layers 302,303, which may help retain the removable material within the gaps 305,306.

In one or more embodiments, the impregnated removable material may beselectively dissolved or removed by way of exposure to a specificremoval material or solvent. As such, in one or more embodiments, theimpregnated removable material may be dissolved from within each of thegaps 305 and 306, which may then allow the slotted liner 300 to functionas a slotted liner, i.e., allow fluid to pass from an outer surface ofthe slotted liner 300 to an inner surface of the slotted liner 300, andvice versa. This may save valuable time in producing production fluidsafter drilling a well bore by using the slotted liner 300 to drill thewell bore and being able to position the slotted liner 300 within thewell bore while drilling the well bore instead of separately installinga slotted liner after the well bore is drilled.

Referring to FIG. 4A, a partial cross-sectional view of a firstcylindrical layer 401 of a slotted liner 400 without a removablematerial (not shown) impregnated in gaps 405 formed therein according toembodiments disclosed herein is shown. As shown, the first cylindricallayer 401 includes a first plurality of triangular elongate members 403having wedge-shaped gaps 405 formed therebetween. Because no polymer isimpregnated in the gaps 405, fluid is free to pass through the slottedliner 400, e.g., in the direction of arrows 410. Those having ordinaryskill in the art will appreciate that fluid may also be free to passthrough the slotted liner 400 in a direction that is substantiallyopposite to the direction of arrows 410. In other words, the gaps 405may allow fluid to pass from an outer surface of the slotted liner 400to an inner surface of the slotted liner 400, and vice versa.

Referring to FIG. 4B, a partial cross-sectional view of a firstcylindrical layer 401 and a second cylindrical layer 402 of a slottedliner 400 with a removable material 420 impregnated in gaps 405, 406formed therein according to embodiments disclosed herein is shown. Asshown, the first cylindrical layer 401 is formed from a first pluralityof members 403 having a triangular cross section, and the secondcylindrical layer 402 is formed from a second plurality members 404having a triangular cross section. Further, as shown, the gaps 405 areformed in the first cylindrical layer 401 between the plurality ofmembers 403, and the gap 406 is formed in the second cylindrical layer402 between the plurality elongate members 404.

In one or more embodiments, a removable material is disposed in one ormore of the gaps 405, 406; in each of the gaps 405, 406 in otherembodiments. The removable material 420 impregnated in each of the gaps405, 406 may be a dissolvable polymer. Further, in one or moreembodiments, the removable material 420 may be stable when exposed to,or in combination with, drilling fluid or pills that may be used. Forexample, the removable material 420 may be chemically stable duringdrilling, thermally stable at drilling conditions, resilient withrespect to frictional forces and other forces that may be encounteredwhile drilling. The frictional forces and other forces that may beencountered while drilling may be caused by the formation, particles indrilling fluid, and rotational forces/bending forces of the downholetool. Furthermore, the removable material 420 may be of high enoughviscosity so as to not flow significantly under such expected downholeconditions.

Once drilling and emplacement of the liner is completed, it would thenbe necessary to remove the removable material. Thus, the removablematerial 420 may also be dissolvable, depolymerizable, degradable orotherwise capable of being broken down and removed from the perforationsor gaps when desired. For example, in one or more embodiments, theremovable material 420 may be a dissolvable polymer impregnated in eachof the plurality of perforations. In one or more embodiments, thedissolvable polymer may be one of a water-stable polymer and anoil-stable polymer. In other words, the dissolvable polymer may be apolymer that does not break down or dissolve when exposed to water oroil based drilling fluids. For example, the removable material may be awater-stable, oil soluble polymer; after drilling with a water-basedmud, an oil-based mud or solvent may be used to remove the removablematerial. In other embodiments, the dissolvable polymer according toembodiments disclosed herein may be a dissolvable polymer that does notbreak down or dissolve when exposed to either a water-based drilling mudor an oil-based drilling mud, but may be removed by other means, such ascontact or exposure to select organic solvents, inorganic solvents, orother means of dissolving, depolymerizing, softening, or degrading ofthe polymer. As such, the removable material according to embodimentsherein may include polymers, gels, or other chemical or physicalnetworks that are water soluble, hydrocarbon soluble, thermallydegradable, thermally unstable, photo-degradable and/or U.V. degradable.For example, the removable material may include a cross-linkedcellulosic network, an acid soluble polyamide, and other materials asmay be readily envisioned based on the above description.

Furthermore, those having ordinary skill in the art will appreciate thatthe removable material 420 may be any material that is removable by wayof exposure to a specific material or substance. For example, theremovable material 420 may be a polymer dissolvable by exposure to aspecific solvent. In one or more embodiments, the dissolvable polymermay be able to sustain high temperature and high pressure downholeconditions without breaking down or dissolving, while still being ableto dissolve when exposed to a specific solvent.

As shown, fluid flow is prevented from an outer surface of the slottedliner 400 to an inner surface of the slotted liner 400, and vice versa.As discussed above, the wedge-shaped geometry and orientation of thegaps 405, 406 may help retain the impregnated removable material 420within each of the gaps 405, 406 when the impregnated removable material420 is under pressure in both the inward radial direction and theoutward radial direction.

According to another aspect of the present disclosure, there is provideda drilling system. The drilling system may include a drilling linerhaving a first cylindrical layer formed from a plurality of cylindricalmembers coupled in parallel, the first cylindrical layer having gapsformed between each of the plurality of cylindrical members, and aremovable material impregnated in the gaps formed between each of theplurality of cylindrical members of the first cylindrical layer, and adrill bit coupled, directly or indirectly, to the drilling liner.

Referring back to FIG. 4A, the slotted liner 400 includes a firstcylindrical layer 401 formed from a plurality of cylindrical members 403coupled in parallel. As shown, the first cylindrical layer 401 includesgaps 405 formed between each of the plurality of cylindrical members403. In one or more embodiments, a removable material (not shown) may beimpregnated in the gaps 405 formed between each of the plurality ofcylindrical members 403 of the first cylindrical layer 401.

In one or more embodiments, the slotted liner 400 may be coupled to adrill bit (not shown). As such, the drill bit may be used to drill wellbore, while also allowing the slotted liner 400 to be positioned whiledrilling. This may eliminate the need to separately install a slottedliner after a well bore is drilled because the slotted liner 400 may becoupled to the drill bit and may be set while drilling the well bore.Alternatively, in one or more embodiments, the slotted liner 400 may becoupled to a bottom hole-assembly (BHA), which may be used to drill thewell bore. Moreover, in one or more embodiments, a drill bit or a BHAmay be coupled to a drill string and may be disposed through the slottedliner 400.

Further, the drilling system may include a second cylindrical layerformed from a plurality of elongate members coupled in parallel, thesecond cylindrical layer having gaps formed between each of theplurality of elongate members, in which the second cylindrical layer isdisposed within the first cylindrical layer, the second cylindricallayer is coupled to the first cylindrical layer, and the removablematerial is also impregnated in the gaps formed between each of theplurality of elongate members.

Referring back to FIG. 4B, the slotted liner 400 also includes thesecond cylindrical layer 402 formed from the plurality of elongatemembers 404 coupled in parallel. As shown, the second cylindrical layer402 includes gaps 406 formed between each of the plurality of elongatemembers 404. In one or more embodiments, a removable material 402 isimpregnated in the gaps 405, 406 formed between each of the plurality ofcylindrical members 403 of the first cylindrical layer 401 and betweeneach of the plurality of elongate members 404 of the second cylindricallayer 402, respectively.

According to another aspect of the disclosure, there is provided amethod of manufacturing a drilling liner apparatus. The method ofmanufacturing may include forming a first cylindrical layer having afirst plurality of perforations formed therethrough, and impregnatingeach of the first plurality of perforations with a removable material.

The method of manufacturing may include, in other embodiments, forming afirst cylindrical layer having a first plurality of perforations formedtherethrough, forming a second cylindrical layer having a secondplurality of perforations formed therethrough, in which the secondplurality of perforations are in fluid communication with the firstplurality of perforations. The method may also include impregnating oneor more of the first and second plurality of perforations with theremovable material so as to prevent or retard flow from the first to thesecond plurality of perforations or vice versa.

For example, in one or more embodiments, a first cylindrical layer maybe formed from a substantially rigid material, e.g., steel, by way offorging, casting, injection-molding, or any other method. Further,perforations may be formed through the first cylindrical layer by way ofcutting, punching, or drilling. Alternatively, in one or moreembodiments, the first cylindrical layer may be formed with perforationsalready formed therethrough by way of molding or casting. Subsequently,a removable material, e.g., a dissolvable polymer 420 shown in FIG. 4B,may be impregnated into each of the plurality of perforations formed inthe first cylindrical layer. In one or more embodiments, theimpregnation of the perforations may be accomplished by submerging thefirst cylindrical layer into the dissolvable polymer, by way ofinjection molding the dissolvable polymer into each of the plurality ofperforations, or any other method.

Further, according to one or more aspects of the method ofmanufacturing, forming the first cylindrical layer may also includeforming a plurality of cylindrical members, coupling the plurality ofcylindrical members in parallel to form a cylinder, in which gaps areformed between each of the plurality of cylindrical members and in whichimpregnating each of the first plurality of perforations includesimpregnating the gaps formed between each of the plurality ofcylindrical members with the dissolvable polymer. Furthermore, accordingto one or more aspects of the method of manufacturing, forming thesecond cylindrical layer may also include forming a plurality ofelongate members, coupling the plurality of elongate members in parallelto form a cylinder, in which gaps are formed between each of theplurality of elongate members, disposing the second cylindrical layerwithin the first cylindrical layer, coupling the first cylindrical layerto the second cylindrical layer, in which impregnating each of thesecond plurality of perforations includes impregnating the gaps formedbetween each of the plurality of elongate members with the dissolvablepolymer.

In one or more embodiments, forming the plurality of cylindrical membersand the plurality of elongate members may be accomplished by way offorging, casting, injection-molding, or any other method. Further, asdiscussed above, coupling each of the plurality of cylindrical membersand the plurality of elongate members may be accomplished by spotwelding or by way of continuous welding, such as with resistivitywelding. Furthermore, as discussed above, in one or more embodiments,the impregnation of the plurality of perforations may be accomplished bysubmerging the first cylindrical layer and the second cylindrical layerinto the dissolvable polymer, by way of injection molding thedissolvable polymer into each of the plurality of perforations, or anyother method.

According to another aspect of the present disclosure, there is provideda method of drilling. The method of drilling may include drilling a wellbore to a pre-determined depth with a drill bit coupled, either directlyor indirectly, to a drilling liner, the drilling liner having aplurality of perforations formed therethrough and a removable materialimpregnated in each of the plurality of perforations, removing theremovable material impregnated in each of the plurality of perforations,and producing a production fluid, in which the production fluid passesthrough the perforations of the drilling liner. In one or moreembodiments, removing the removable material may include pumping asolvent configured to dissolve the removable material impregnated ineach of the plurality of perforations.

As discussed above in reference to FIG. 4B, the slotted liner 400 may becoupled, either directly or indirectly, to a drill bit (not shown). Assuch, the drill bit may be used to drill well bore, while also allowingthe slotted liner 400 to be positioned while drilling. As such, thiseliminates the need to separately install a slotted liner after a wellbore is drilled because the slotted liner 400 may be coupled to thedrill bit and may be set while drilling the well bore. Alternatively, inone or more embodiments, the slotted liner 400 may be coupled to abottom hole-assembly (BHA), which may be used to drill the well bore.Moreover, in one or more embodiments, a drill bit or a BHA may becoupled to a drill string and may be disposed through the slotted liner400.

Embodiments disclosed herein may allow the slotted liner 400 to be usedas both a non-perforated liner, which may be used to pump mud to thedrill bit/BHA, and a perforated liner, which may be used to filterdebris from production fluid. For example, while drilling, theperforations of the slotted liner 400 may be impregnated with thedissolvable polymer 420 such that drilling mud may be pumped through theslotted liner 400 to the drill bit/BHA without escaping through theperforations, which may be accomplished with assistance from thewedge-shaped geometry and orientation of the gaps formed in the slottedliner 400, as discussed above, in which the design of the gap, which maybe perpendicular gaps, retains the removable material within the liner.In other words, by impregnating the perforations of the slotted liner400 with the dissolvable polymer 420, the slotted liner 400 may functionas a non-perforated liner or casing during the drilling process.Allowing mud to be pumped through the throughbore of the slotted liner400 may help straighten the slotted liner 400 and may also prevent drillcuttings from u-tubing into the annulus between the liner and the drillstring/BHA. Once the slotted liner 400 is desirably positioned downhole,the specific solvent may be pumped through the slotted liner 400 todissolve the impregnated dissolvable polymer 420. In one or moreembodiments, the removal of the impregnated dissolvable polymer 420 byway of exposure to the specific solvent may soften, dilute, or acidizethe dissolvable polymer 420 and may allow the dissolvable polymer 420 tocirculate out of the perforations of the slotted liner 400.

Instead of taking the time to separately install a slotted liner after awell bore is drilled, a specific solvent may be pumped through theslotted liner 400, which may dissolve the dissolvable polymerimpregnated in each of the plurality of perforations. This may allow theslotted liner 400 to be used to allow production fluid to pass into theinterior of the slotted liner 400 and flow up toward the surface whiledebris, such as sand, gravel, etc., is be filtered by the slotted liner400.

Although only a few example embodiments have been described in detailabove, those skilled in the art will readily appreciate that manymodifications are possible in the example embodiments without materiallydeparting from this disclosure. Accordingly, all such modifications areintended to be included within the scope of this disclosure. In theclaims, means-plus-function clauses are intended to cover the structuresdescribed herein as performing the recited function and not onlystructural equivalents, but also equivalent structures. Thus, although anail and a screw may not be structural equivalents in that a nailemploys a cylindrical surface to secure wooden parts together, whereas ascrew employs a helical surface, in the environment of fastening woodenparts, a nail and a screw may be equivalent structures. It is theexpress intention of the applicant not to invoke 35 U.S.C. §112,paragraph 6 for any limitations of any of the claims herein, except forthose in which the claim expressly uses the words ‘means for’ togetherwith an associated function.

What is claimed is:
 1. A drilling apparatus comprising: a firstcylindrical layer including a plurality of cylindrical members; and asecond cylindrical layer including a plurality of elongate members, theplurality of cylindrical members and the plurality of elongate membersarranged to form a plurality of gaps between an outer diameter of thefirst cylindrical layer and an inner diameter of the second cylindricallayer.
 2. The apparatus of claim 1, further comprising: a removablematerial impregnated in one or more of the plurality of gaps formedbetween the outer diameter of the first cylindrical layer and the innerdiameter of the second cylindrical layer, wherein the plurality ofcylindrical members and the plurality of elongate members are arrangedto retain the removable material in the plurality of gaps formed betweenthe outer diameter of the first cylindrical layer and the inner diameterof the second cylindrical layer.
 3. The apparatus of claim 2, whereinthe removable material is one of a water-stable polymer and anoil-stable polymer.
 4. The apparatus of claim 1, wherein the firstcylindrical layer is formed from the plurality of cylindrical memberscoupled in parallel and defining gaps formed between one or more of theplurality of cylindrical members, and a removable material isimpregnated in one or more of the gaps formed between one or more of theplurality of cylindrical members of the first cylindrical layer.
 5. Theapparatus of claim 4, wherein a cross-section of the plurality ofcylindrical members is triangular.
 6. The apparatus of claim 4, whereinthe gaps formed between the plurality of cylindrical members aresubstantially wedge-shaped, wherein an apex of the wedge-shaped gaps isoriented near an outer diameter of the first cylindrical layer.
 7. Theapparatus of claim 1, wherein the second cylindrical layer is formedfrom a plurality of elongate members coupled in parallel having gapsformed between one or more of the plurality of elongate members.
 8. Theapparatus of claim 7, wherein a cross-section of the plurality ofelongate members is triangular.
 9. The apparatus of claim 8, wherein thegaps formed between one or more of the plurality of elongate members aresubstantially wedge-shaped, wherein an apex of the wedge-shaped gaps isoriented near an inner diameter of the second cylindrical layer.
 10. Theapparatus of claim 7, wherein the second cylindrical layer is disposedwithin the first cylindrical layer, the second cylindrical layer iscoupled to the first cylindrical layer.
 11. The apparatus of claim 7,wherein the plurality of cylindrical members extend in a firstdirection, and the plurality of elongate members extend in a seconddirection, wherein the first direction is substantially perpendicular tothe second direction.
 12. A drilling system comprising: a drilling linerhaving a first cylindrical layer formed from a plurality of cylindricalmembers coupled in parallel, a second cylindrical layer formed from aplurality of elongate members coupled in parallel, the plurality ofcylindrical members and the plurality of elongate members arranged toform a plurality of gaps between an outer diameter of the firstcylindrical layer and an inner diameter of the second cylindrical layer,and a removable material impregnated in the plurality of gaps formedbetween the first cylindrical layer and the second cylindrical layer;and a drill bit coupled to the drilling liner.
 13. The system of claim12, wherein the removable material is a dissolvable polymer configuredto dissolve through contact with a specific solvent.
 14. A method ofmanufacturing a drilling liner apparatus, the method comprising: forminga first cylindrical layer having a first plurality of perforationsformed therethrough; forming a second cylindrical layer having a secondplurality of perforations formed therethrough, wherein the secondplurality of perforations are in fluid communication with the firstplurality of perforations; and impregnating one or more of the firstplurality of perforations and the second plurality of perforations witha removable material,
 15. The method of claim 14, wherein forming thefirst cylindrical layer comprises; forming a plurality of cylindricalmembers; and disposing a plurality of cylindrical members in parallel toform a cylinder, wherein impregnating one or more of the first pluralityof perforations includes impregnating gaps formed between one or more ofthe plurality of cylindrical members with the removable material. 16.The method of claim 14, wherein forming the second cylindrical layercomprises: forming a plurality of elongate members; and disposing aplurality of elongate members in parallel to form a cylinder, whereinimpregnating one or more of the second plurality of perforationsincludes impregnating gaps formed between one or more of the pluralityof elongate members with the removable material.
 17. The method of claim14, further comprising: disposing the first cylindrical layer within thesecond cylindrical layer; and coupling the first cylindrical layer tothe second cylindrical layer, wherein gaps are formed between one ormore of the cylindrical members and between one or more of the pluralityof elongate members.
 18. The method of claim 14, wherein impregnatingone or more of the first plurality of perforations includes one ofsubmerging the first cylindrical layer into the removable material andmolding the removable material into one or more of the first pluralityof perforations.
 19. A method of drilling comprising: drilling a wellbore to a pre-determined depth with a drill bit coupled to a drillingliner, the drilling liner having a plurality of perforations formedtherethrough and a removable material impregnated in one or more of theplurality of perforations; removing the removable material impregnatedin one or more of the plurality of perforations; and producing aproduction fluid, wherein the production fluid passes through thedrilling liner.
 20. The method of claim 19, wherein the drilling linerincludes a first cylindrical layer formed from a plurality ofcylindrical members coupled in parallel, the first cylindrical layerhaving gaps formed between one or more of the plurality of cylindricalmembers, and the removable material impregnated in the gaps formedbetween one or more of the plurality of cylindrical members of the firstcylindrical layer.